Question

what is larmor radius for electron and ion?

Answer 1

The Larmor radius for an electron with a mass $m_e$ and charge $e$ moving in a magnetic field $B$ perpendicular to the velocity of electron $v$ can be calculate as

$$r=\frac{m_ev}{eB},$$

substituting the numerical values, we get

$$r(v,B)=\frac{5.686\cdot10^{-12}\cdot v}{B}.$$

For an ion of mass $m$ and charge $q$ , the same equation can be applied under the conditions stated above:

$$r=\frac{mv}{qB}.$$